Gradle: Migrate top-level build files to Kotlin DSL

Migrate the top-level build files to the new Kotlin DSL and use the new
pluginManagement block instead of the old buildscript.

settings.gradle.kts

@@ -0,0 +1,36 @@
+pluginManagement {
+    repositories {
+        google {
+            content {
+                includeGroupByRegex("com\\.android.*")
+                includeGroupByRegex("com\\.google.*")
+                includeGroupByRegex("androidx\\..*")
+            }
+        }
+        gradlePluginPortal()
+        mavenCentral()
+    }
+}
+dependencyResolutionManagement {
+    repositoriesMode = RepositoriesMode.FAIL_ON_PROJECT_REPOS
+    repositories {
+        google {
+            content {
+                includeGroupByRegex("com\\.android.*")
+                includeGroupByRegex("com\\.google.*")
+                includeGroupByRegex("androidx\\..*")
+            }
+        }
+        mavenCentral()
+        maven("https://jitpack.io") {
+            content {
+                includeGroupByRegex("com\\.github\\..*")
+            }
+        }
+    }
+}
+
+rootProject.name = "Gadgetbridge"
+
+include(":app")
+include(":GBDaoGenerator")